Evident Escalation
by Lord of Kavaka
Summary: She always hated the phrase "one thing led to another". One thing did not lead to another. Never did. Yet despite that fierce belief, Kate Beckett could not deny the truth that yes, one thing had led to another, resulting in her bringing her annoying, self-absorbed, jackass of a shadow back to her apartment after wrapping up the case. Tick, Tick, Tick/Boom AU. For CastlePornado2019


**Evident Escalation**

* * *

She always hated the phrase "one thing led to another" because she just found that to be utter bullshit. One thing _did not_ lead to another. Never did. It was just something people said to excuse rash actions and decisions. People made choices, conscious decisions in their actions. And they should accept the consequences of those actions rather than trying to excuse them as simply being inevitable because of circumstances. Yet despite that fierce belief, Kate Beckett could not deny the truth that yes, one thing _had_ led to another, resulting in her bringing her annoying, self-absorbed, jackass of a shadow back to her apartment after wrapping up the case.

Yeah, she could make other commonly used excuses. Their emotions had been heightened by the dramatic and intense shared experience of this particular case, drawing each other to one another. The adrenaline wouldn't go away and she needed an outlet, and he was a convenient and easily eager one, more than happy to oblige. After all, he had spent a good portion of a year following her around during the course of her work, making no secret that he wanted into her pants. But she had always refused him, rebuffed his advances and scoffed at his innuendos.

But now, after the past several intense days, where a deranged killer had focused on her, needing to challenge her fictional alter ego Nikki Heat to feed his delusions, all the interplay, back and forth, and banter just came to a head. One moment they were standing on the street, staring at one another, listening to FBI Agent Jordan Shaw proclaiming the case was all wrapped up with the suspect dead, and the next they were tumbling around in her bed, frantically tugging at clothes in-between desperate, deep, life-affirming kisses.

Kate didn't want to think just how wonderful his lips were, how she reacted to the simple touch of his hands sensually roaming her body, peeling off her blouse, nudging her bra aside. No. She didn't want to think about her whimpers and pleas as he feasted on her naked chest, cupping and kneading her breasts with expert skill, as if it wasn't something completely new to him, like this sort of intimate touching was just natural to them, something they'd always done.

She wanted to void her mind of the way she nudged him back, desperately yanking on his belt to undo the buckle and unzip his trousers. No way in hell did she want to revisit the excited eagerness of her hands as she freed him from the constraints of his boxers and touched him with her nimble fingers, before awakening him with her hot and hungry mouth, sucking him in, twirling her tongue, memorizing the way his breath hitched and hissed as she showed him some of her hidden talents until he was at full standing.

Things escalated quickly from there. He had her jeans and panties off in no time, using his fingers to tease and taunt her before adding his wicked tongue to the mix. God, he was good. He brought her to orgasm faster than she cared to admit. Castle definitely had a talented tongue, which he could use in more inventive and creative ways than she had thought possible. Damn, it was good. Better than good. It was fantastic, mind-blowing, earthshattering, any and all adjectives that could possibly be used to describe it should and would, Kate just couldn't form a coherent enough thought to give them voice.

The arrogant bastard had a smug smirk plastered on his handsome face when she came down from her high, but she wiped it off soon enough, flipping them until she was on top, straddling him with her powerful thighs. She stretched over him, purposely brushing her breasts across his face as she reached for the bedside drawer and the condoms inside. Taking one out, she sat back on his legs and wrapped one hand around his length, almost salivating with anticipation as she rolled the protection over him. Then she was rising up and sinking, ever-so-slowly—she'd had a pretty long dry spell, so she needed time to adjust to the welcomed intrusion—down on top of him, engulfing and surrounding him, feeling him fill her just right, so very right.

Once fully settled, Kate Beckett rode Richard Castle hard and fast, like he was some prized stallion, bucking and rotating her hips at a frenzied pace that he matched, stroke for stroke, thrust for glorious thrust. His hands gripped her hips, helping to guide her motions. She bent over him, kissed him, claiming him as hers. Her shadow. Her stud. Her partner.

Before she knew it, he was rolling them over, pinning her underneath his broader frame. He leaned back, yanked his shirt of, sending buttons flying to the floorboards. Castle let out an almost animalistic growl, lowering back down over her, kissing her deeply, his tongue invading, doing battle with hers. Kate chased after him when he pulled away, nipping at the empty air, but she didn't have long to wait, soon he was plunging back inside her, stretching her wide and pumping his hips like an engine piston. He gripped her, just above her hipbones, tilting her pelvis to change the angle just enough to allow him to hit that sweet spot that other lovers had needed coaching and instruction to find.

Kate cried out, dropping her head back into the pillows as both her body and the mattress shook with the vigor of his thrusts. She clawed at the bedspread for support, soon finding herself overwhelmed by each and every stroke of him inside her, the sensations coiling low in her belly both familiar and foreign. The sensual sound of their flesh slapping together resounded through her bedroom, and Kate let out a stuttering moan, arching her neck up to stare raptly down at their intimate connection, the sight making her whimper and shudder with pleasure. Regaining enough concentration to participate once again, Kate rolled her hips in time with his, stretching up to brush her hands down his torso. She let her fingers roam over his solid frame, memorizing the way his muscles tensed and relaxed with each thrust of his hips.

Castle grinned at her, increasing the pace as he bent over her, slanting his mouth over hers as he continued to move his hips like a master, knowing just how to thrill and excite her. He really didn't disappoint as a lover. Castle nibbled down the column of her neck, sucked on her pulse point, making her whimper. Their chests pressed together as he cradled her closer. Her hands snaked around and down his back, and she latched onto the plump flesh of his ass. He had a magnificent ass. She'd admired it from afar for longer than she'd care to admit, daydreaming of digging her fingers into it. Kate squeezed and urged him on, gasping his name in hot, panting breaths.

And then, after several more powerful thrusts, Castle sent her over the edge for a second time that evening, and soon followed.

Her body arched and bowed, and her moans of pure pleasure filled the silence of her apartment. For a first time, it was pretty spectacular. No other lover had been so in tuned with her needs and wants during their first sexual encounter. Somehow, Kate had always known it would be different with Castle. The way they built theory together was proof enough how in sync they could be. And it wasn't really that big of a surprise it would translate into the bedroom just as well.

Castle spun them back over, cradling her lax body against his. Spent, she collapsed on top of him and he wrapped his arms around her, holding her to him as they lazily shared soft and intimate kisses, far too intimate for a first time. Kate refused to dwell on what that meant. Instead, she simply basked in the glorious sweaty heap of flesh they made together.

And now they were sharing a shower. The intervening time was a blur of lazy, soft, post-coital bliss. Yet somehow, someway, she had found the strength to pull herself out of bed and haul his magnificent ass with her to the bathroom.

It was cramped in the shower. Well, to be honest, it wasn't really a shower, not in the typical sense when most people thought of a shower. Just a cast-iron clawed tub with a shower head attached. It wasn't small, yet neither was it large. There was barely enough space for both of them to move about comfortably. Kate closed her eyes, and pirouetted in place, turning her back to the spray of hot water. Blinking her eyes, she tilted her chin and stared up at Castle. He was looking at her with such awe and admiration that she found herself speechless.

"I have a confession to make," he said, gently trailing his fingers down her naked side, making her shiver despite the steam and warmth.

"What is that?" she asked, biting her lower lip.

Castle hesitated, appearing unsure. It was so uncharacteristic of him to show any self-doubt or anxiety, especially considering the activities they had just engaged in, which led her to believe whatever he was about to say was serious, and not some joke. She pursed her lips and swallowed.

"Castle?" she prompted, growing unnerved standing there in the shower, feeling so open and exposed, and not just because she was naked.

He heaved in a deep breath, and she tried not to stare at his impressive broad frame as his chest rose and fell. Castle gathered whatever courage he needed, and narrowed his gaze in on her eyes.

"I think I might be falling in love with you," he all but blurted out.

He clenched his eyes shut and winced, as if expecting her to strike him with a fist. But she did not. Her breath left her lungs and her knees felt weak. She wasn't exactly sure what she had been expecting him to say, but it was definitely not that. Kate furrowed her brow, so confused. Glancing up at him, she tried to find a proper response, but she wasn't good with words. Kate knitted her eyebrows together and mulled over the last few days, specifically the last hour or two, and all the things—_the stirrings_—she'd ignored, pushed aside, denied over their time working together.

Her actions, dragging him back home to her bed, having sex—amazing, mind-blowing sex—with him wasn't her. She wouldn't just do that unless there was a reason behind it. Kate Beckett did not do one night stands. At least, not anymore. And definitely not with arrogant assholes like Rick Castle.

Dear God. It was like being slapped in the face. She blinked, stunned by the revelation, feeling her chest tightened with a hint of panic and fear, the desperate need to run, just run away. But she didn't. His presence beside her kept her tethered, anchoring her to the present, to that moment. That, and the fact she was completely naked and soaked, and not just from the water.

"Caste… I…"

He shushed her with a soothing touch of his fingers to her lips. "You don't have to say anything, Beckett," he assured. "I just thought you should know. I didn't really realize it myself. Not until this case, when my words put you in the crosshairs of a killer. I thought it was just an infatuation, something I needed to get out of my system."

She scoffed at that, making him grin.

"But you're not," he went on, smiling down at her with such sincerity that she believed him. "I'll never get enough of you. Never." He paused, gathering her close in his arms. Her slim body pressed firmly up against his broader frame, and oh… yeah, she could feel just how much he wanted her. "It stunned me, Beckett, the truth of it all."  
"What truth?" Kate managed to ask, mildly distracted by the hot and hard length pressing into her belly.

"It's not about the books anymore," Castle said, earnest and real. "It never was. Not really. You're not a notch on my bedpost. You're not just some conquest."

That stunned her.

Sure, his earlier declaration that he might be falling in love with her had done the same, but his latest statement was just further evidence of his feelings for her, feelings she was beginning to suspect she reciprocated. But she wasn't quite sure how to respond. She wished she had his way with words, but she didn't. Kate Beckett was a woman of action. So instead, she pushed up on her toes and claimed his mouth in a passionate embrace that spoke more than words ever could. Parting for air, she nudged her nose against his and then arched up to brush her lips against his ear in a similar fashion as she had when they'd closed their first case, but this time, she had different words to say.

"Prove it."

She pulled back to look him in the eye, raising one brow in challenge.

And he accepted.

Castle dove in, seizing her mouth in a searing, soaring kiss that had her toes curling. She wrapped her arms around his neck and pushed in closer to him, moaning as his hands skimmed down her back to cup her ass, squeezing. He continued his assault on her mouth, ravishing her, his passion having never fully waned.

Kate groaned as he nipped his way down the column of her neck, teasing her pulse point with a little nibble. She didn't care if he left his mark, she already had plans of leaving one of her own in exchange. She closed her eyes, tilting her head back to expose more of her throat, giving him room to work with as he licked and sucked and kissed. The hot water sprayed down from the shower head, cascading down her back, making her all warm and relaxed, open and ready for whatever her companion had in mind.

Keeping one hand on her ass, clenching the firm muscle tightly, Castle shifted one hand up her body to palm her breast. He kneaded the soft flash perfectly, flicking a thumb out to tease her nipple. She gasped and he grinned.

Smirking in return, she leaned back enough to reach down between them and wrapped her nimble fingers around him. He groaned as she stroked him, taunting him as much as he taunted her.

"I said prove it, Castle," she grinned, flicking her eyes up at him and biting her lower lip alluringly. "So prove it."

He huffed, and yanked her hand away. He gripped her thigh and tugged it up, pulling her closer. Kate's heart rate quickened when she felt their centers align as he hooked her leg around his hip. She wiggled one hand down between their heaving bodies and found him, hot and ready. He closed his eyes and leaned his forehead against hers. She guided him to her, rubbing the head of his cock against her folds, and then with an almost aggressive thrust of his hips, he was buried inside her.

Kate let out a moan as he filled her completely, a perfect fit. Never before had such an intimate connection felt so right. She gripped his shoulders for support as he began to thrust, shallowly at first, allowing her to adjust to his sudden but welcomed intrusion. He kept one hand on her ass, holding her in place as he pumped back and forth, in and out. She whimpered and squirmed, rotating her hips to take more of him in. Wanting more. Always more. And soon they found their rhythm in the awkwardly confined space of her shower tub. But they made it work. Somehow, Kate just knew that they'd always find ways to make it work.

"Yes, Castle," she cried as she rocked in time with him, keeping her right leg firmly locked around his left hipbone, their centers perfectly aligned. "Yes."

The water tumbled down and between their bodies, making their flesh warm and slick. Kate grinned wickedly, having more fun than she'd ever had before, and laughed as she playfully slapped his plump ass. Castle kissed her softly, slowing the pace for a second, before digging his hands into her sides and rocketing up the momentum. Kate felt her insides come alive with it, the warmth coalescing in her center. She hooked her leg up higher around his hip, giving him more access, changing the angle just enough for him to hit that sweet spot on the next stroke. Crying out in ecstasy, Kate let the orgasm surge through her, seizing her body as Castle plunged deeper into her with each powerful thrust.

As she screamed in unadulterated pleasure, the whole world seemed to shake. Her vision went white. And her entire body seemed to burn with the flames of passion.

But then her back was slamming into the floor of the tub, and Castle was crowding her in, his pelvis pressed close to her, his length still buried deep inside her, and she blinked through the stars to see that there really were flames shooting up around them. Castle was protectively cradling her against his bowed body, using his broader frame to shield her from the raging heat.

"That was one hell of an explosive finale," she grunted into his shoulder, and his body shook with laughter, making her groan as a burst of pleasure rippled through as his movement caused some delicious friction from their connection.

"Finale?" He huffed out a chuckle. "I was just getting started."

When the initial blast subsided, Castle leaned back enough to gaze down at her. One hand swept up to brush tenderly down the side of her face as he looked at her with deep concern in his blue eyes.

"You okay? Hurt?" he asked.

"I'm fine," she huffed out, squirming under him, only reminding her of the fact they were still intimately connected. Kate let out a panting moan and clenched around him, surprised at how close she was to another orgasm considering the present circumstances. A groan left Castle's lips, just as a whimper slipped from hers. She gritted her teeth, trying to control her body's natural reaction to his. "You? Are you hurt?"

"I think I'm okay," he grunted, shifting slightly above her, making them both gasp from the movement. "I think the tub shielded us from the blast." His hand moved around as he groped for purchase. She yelped in surprise when he accidently palmed her breast. He offered a goofy grin and apologized, but she shook it off. It had been an accident, besides, considering what they'd been in the middle of doing earlier, such an intimate touch was nothing to get riled up over.

"Move Castle, get off me, I can't breathe," Kate said, shoving at his chest.

Castle did as she instructed, but as he moved back Kate felt him slip out of her and she couldn't help but let out a whimper of disappointment at the loss of their connection.

"What the hell happened?" she asked as Castle craned his neck up to peer over the edge of the tub.

"Um," he glanced back at her with a nervous expression. "You're not going to like this, but I think your apartment just blew up."

"What!?" she hissed, pushing him aside to get a look for herself. She gripped the edge of the tub and hauled herself up, eyes going wide when she saw he was right.

"_Nikki will burn_," Castle mumbled.

Kate snapped her head back to him. "What?"

Castle looked at her, eyes frantic. "_Nikki will burn_," he repeated. "That's the phrase we found in his apartment, repeated over and over again."

She was not following him. Her mind was on overload from the odd combination of the mind-blowing orgasm and the apparent explosion that had just engulfed her apartment.

"Castle," she barked, easily garnering his attention. "Explain."

"The case. It was all wrapped nice and neat."

"That's a good thing."

"In a book, yes, but in real life, nothing is that neat," Castle asserted. "The bruising pattern on the second victim—the killer used his left hand."

Kate knitted her eyebrows together, trying to recall the case details. She mentally visualized the evidence and clues as Castle described them.

"And his handwriting? The slope of the '4' and the loop of the '6'," Castle pointed out.

She nodded, finally latching on and following his logic. "He was left-handed."

Castle stared at her, wild eyed. "Well, Ben Conrad shot himself with his right hand. If the man in the window was Ben Conrad, he would've shot himself on the left side. Ben Conrad didn't kill himself. Ben Conrad was murdered by the man in the window. Ben—Ben's not our killer, Beckett. The real killer was just playing with us."

"But the evidence—"

"No, it was—it was planted there to lead us to Ben," Castle insisted, shaking his head, firm in his conviction.

Kate was starting to believe him too, which was easier with the evidence of her burning apartment as further proof that Ben Conrad was a patsy for the real killer. "He wanted us to drop our guard. He wanted to make a big scene," she added, glancing back out at the smoldering ruins of her apartment. "Oh my God, Castle, if we hadn't been in the shower—"

"No," he cupped her jaw, forcing her to look at him. "Don't even think it."

There was nothing left that wasn't in flames or dirtied by the blast to cover themselves, so they had to just sit there and wait for the indignity of being found by the firefighters in the shower tub, naked. And, sure enough, when the first responders arrived, there was a bright exchange of looks and chuckles as the men easily surmised what Kate and Castle had been up to in the shower when the explosion had occurred.

The whole ordeal was mortifying, but thankfully by the time the boys and FBI Agent Jordan Shaw arrived on scene, both her and Castle were dressed in FDNY sweatshirts and sweat pants. Though, from the look on Shaw's face, the FBI Agent had their number almost immediately. The boys, however, took a while, but once they caught on to the circumstances, they started in on the teasing, which Kate managed to shoot down with a fierce glare. Still, it was all incredibly embarrassing.

They parted soon after, not really having time to discuss what had occurred between them prior to the explosion. Kate went all business, focusing on the case, relooking at everything they had on Ben Conrad. She was grateful for the pair of back-up clothes she kept in the gym locker at the precinct, because with her apartment in flames, she really didn't have anything to wear. Castle eventually met up with her in the bullpen, and joined in in digging for more information on Ben Conrad, trying to piece together how the killer used him to fool them.

Eventually, after running down some new leads, they found another patsy. His apartment was made up to look like a stalker's wet dream. They found a manifesto, of shorts, a manuscript entitled _Dead Heat_, where the killer had written out everything about the previous murders, having Nikki Heat attempting to solve the crimes, but always one step behind the killer. She noticed Castle looked uneasy about the discovery. Kate felt drawn to him, wanting to comfort him, but she couldn't, not while they were in the middle of working the case.

Back out on the street, Kate caught sight of a suspicious individual. When she ordered him to stop, he took off. She ran after him, but despite her best efforts to catch him, he managed to allude her, reaching the subway right a head of her.

Later, with the help of the FBI's fancy equipment, they were able to identify their suspect as Scott Dunn. Kate was juiced, pumped, ready to go after him and nail the son of a bitch, but Agent Jordan Shaw benched her. And when she went to complain to Montgomery, her captain backed up the FBI Agent. He told her to go home, and through a clenched throat she reminded him that she didn't have one anymore.

"Yes, you do," Castle startled her with his declaration. She glanced over at him, saw the look in his eyes and averted her gaze, knowing his feelings for her were all but beaming out. "It's a secured building, with an extra bedroom, with people who care about you, with a federal detail at the door. It's the safest place in the city."

"Thank you, Castle, but I couldn't," she said, not entirely ready to confront things.

"You can and you will," Castle insisted.

Montgomery ended the debate, ordering her to go home with Castle, and from the twinkle in his eye as he did so, Kate just knew that the boys had brought him up to speed with what they'd gleamed from the circumstances surrounding the explosion of her apartment. She gritted her teeth, but held her tongue, reluctantly agreeing to obey her orders.

Kate felt strange being in Castle's loft, considering the shift in their physical relationship. They hadn't yet talk about it, and she wasn't relishing it. Kate didn't understand where all this hesitancy was coming from. She certainly didn't have any of it last night. She was bold, and brazen, taking and giving what she wanted without thought or care of the consequences.

Well, sitting here alone with Castle, she had to deal with those consequences. She didn't regret what they had done, far from it, but there was a part of her that felt that perhaps it was too soon. She was afraid that the partnership she had come to rely on would suffer if their romance didn't work out. Avoiding the subject, Kate chose to remain silent and sit at the dining room table as Castle made her a cup of hot chocolate.

"Here you go, added some extra marshmallows," he grinned as he sat down opposite her with his own cup.

"Thanks," she smiled weakly, and took a tentative sip. "It's good."

"After the day we've had, you deserve it," he assured her with a playful wink. Why did he have to be so sweet?

"Yeah," she let out a hollow laugh. "Well, who would've thought that I would be homeless and caseless in one day?"  
"I know I'm the king of going rogue," Castle asserted, putting his cup down and leaning forward, "But you were right to chase after Dunn."

Kate sighed and dropped her gaze to the cup of hot chocolate in her hands. "And Agent Shaw was right to kick me off the case," she admitted. "I would've done the same thing if I was in her spot. I'm too close to it."

Castle hesitated, frowning as he glanced down before looking back up to meet her questioning gaze. "I'm sure you, after all this, you're a little sorry you let me follow you around."

"No," Kate said after a moment's thought, cocking her head and letting him squirm. It was too much fun not to. "Not this. All the other annoying things that you do, but not this."

He hummed in response, still looking uncertain.

"What about you?" she asked, knitting her eyebrows as she assessed him with curious eyes, seeing the wheels in his head churning. "Are you sorry that you ever wrote _Heat Wave_?"

Castle thought over his response for a second before answering. He shook his head. "The way I look at it now, if it wasn't for Nikki Heat, this guy would've just gone on killing because he wouldn't have met anyone smart enough to catch him."

That made her smile, and her heart quickened at the look in his eyes as he stared at her. She took a deep breath, decided she better confront the elephant in the room.

"About last night—"

"You regret it?" he finished, looking crestfallen.

"No, I didn't say that," Kate offered him an irritated glare for not letting her finish. "I just… I don't know what I wanted to say, but I know we have to talk about it… that… well… you know, that we…" she started to fumble, hoping he'd just fill in the blanks without it needing to be said.

"Had sex," he supplied with a delighted grin. Smug bastard.

Her cheeks turned a rosy shade of pink as she blushed. "Yes, that."

"It was good."  
"Better than good," she amended with a nod, feeling her lips stretch into a wide smile, all teeth and gum, at the memories of the stupendous orgasms she'd had as a result of their coupling.

He shifted in his seat and reached out across the table to grasp her hand. She tensed at first, but forced herself to relax. After all, they had done far more intimate things than holding hands last night.

"Beckett… Kate," he said in a low, serious voice, shifting to the use of her first name. "If there's one thing I've learned during this case it's that I can't lose you. I care about you too much. Far more than I ever expected, to be honest. I meant what I said last night, in the shower. I'm falling in love with you. You don't have to say anything," he quickly asserted before she could respond. "I just… I want to be in your life, in whatever way you'll allow. I'd prefer…" he waggled his eye brows suggestively, "but I'll take what I can get, whatever you give, whatever you want, Kate. I'm yours. Always."

Kate stared at him for a long beat, thinking about that. What did she want? Her heart yearned for more with him, but her brain was wary of taking that risk. She'd been burned before, and there was still the matter of a wall she'd constructed around her heart. But, somehow, she had a feeling Castle might just be the right person to help her dismantle it. She chewed on her lower lip as she debated the pros and cons.

"It was pretty good, wasn't it?" she said, feeling a nervous chuckle escape her lips as she tried to buy herself more time to think. She wasn't used to being so indecisive, but being with Castle, truly being with him, was an important decision, and she wanted to give it the proper amount of thought before committing to anything.

"Better than good," he echoed her earlier statement with a delight smirk, and adding, "The best."

Oh, yeah, she definitely agreed with that addendum. It had been the best. But she wasn't about to confirm that. Not yet. Heaving in a deep breath, Kate made her decision. The future wasn't written. She couldn't keep living her life wondering and hiding away. They could have died last night in that blast, but they didn't. It made her think.

She didn't want to be left dwelling on regrets and if onlys. She liked Castle… a lot. She might even be falling in love with him. She wasn't completely there yet, but she could feel herself sliding that direction. Kate had been hurt before, but from the earnest look reflecting back at her from his ruggedly handsome face, she concluded that perhaps it was worth taking the risk when they could be so great together. And last night had proven just how great they could be, in bed at least, she already had ample evidence just how well they worked out of bed, but it seemed the proof of the former was the final piece to the puzzle.

Kate Beckett was a woman of action, not words. So, instead of answering him verbally, she simply stood up and grabbed his hand. Castle rose from his chair and followed as she guided him out of the dining room.

"Um… Beckett?" Castle questioned, brow furrowed. "I wasn't joking back at the precinct. There is an extra bedroom."

"I know," Kate tossed him a sultry look over her shoulder, adding an extra sway to her hips as she smiled, tugging him towards his office and the bedroom that waited beyond. "Don't need it. I think your bed will do just fine."

* * *

**THE END**


End file.
